1. Field of the Invention
The present invention refers to a method of discharging a substance contained in a cartridge or the like from said cartridge. The substance in the cartridge is prevented from flowing out in the initial condition of the cartridge by a sealing member provided at the outlet of the cartridge.
Further, the present invention refers to an apparatus for dispensing a substance which must be stored in the absence of air. The apparatus comprises a cartridge containing said substance to be dispensed. The cartridge has an outlet opening covered by a sealing member and a piston member inserted into the cartridge at the end opposite to said outlet opening. The piston member sealingly closes the end opposite to said outlet opening and is slidably received in the interior of the cartridge. Means are provided for sliding the piston member into the cartridge to thereby exert a pressure on the substance contained in the cartridge.
2. Prior Art
Power-driven means for the application of multi-component substances are known in the art. Particularly, these means are used to apply a two-component adhesive material to two objects to be adhesively connected one to each other. The apparatus used for this purpose comprise two cartridges containing each a reactive component. The two components have to be mixed together to form the adhesive substance. Thus, ejection members are provided to discharge the content of each cartridge simultaneously to a mixing means in which they are thoroughly mixed whereby a chemical reaction between the two components starts. The adhesive substance prepared in this way is discharged through an outlet nozzle of the mixing means and applied onto the objects to be glued together.
According to the prior art, the cartridges containing the reactive substances are brought into operating condition and, thereafter, inserted into the apparatus. However, the discharging of the cartridges often presents difficulties. The cartridges are provided with a piston-like ejection member slidably mounted in the interior of the cartridge. Since the ejection member can not seal the interior of the cartridge perfectly, the cartridges are provided with a cover member in order to safely avoid atmospheric air from gaining access to the interior of the cartridge and, thereby, to the substance contained therein during storage of the cartridge. This measure must be taken because an unintended contact of the substance contained in the cartridge with atmospheric air could trigger an undesired preliminary chemical reaction of the substance contained in the cartridge.
Such a cover member, however, prevents or at least impedes the access to the piston-like ejection member.
The other end of the cartridge provided with an outlet opening must be sealed as well during storage of the cartridge in order to avoid access of atmospheric air to the content of the cartridge up to the moment when the cartridge is used. Thus, in order to prepare the apparatus for operation, it is not only necessary to insert the cartridges, usually two, into the apparatus, but also to open the cover at the end of the piston-like ejection member as well as the sealing at the outlet end of the cartridge. This proceeding is particularly difficult and cumbersome to perform in the case when the cartridges form a unit with the mixing means and the tubular means connecting the cartridges to the mixing means, ready to be inserted as a whole into the apparatus. In this case, the outlet openings of the cartridges provided with a sealing cover means are not accessible with the result that the cartridges have to be released from the associated connecting tube in order to enable an operator to remove the sealing cover means at the outlet opening. Consequently, the use of ready-to-use units, consisting of e.g. two cartridges, a mixer and two connection tubes connecting the two cartridges to the mixer, preferably in the form of units which can be disposed after use, was not possible. Such units, on the other hand, would be very practical, safe and time saving.